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f4681817 MD |
1 | /* |
2 | * lttng-ust-abi.c | |
3 | * | |
4 | * Copyright 2010-2011 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
5 | * | |
6 | * LTTng UST ABI | |
7 | * | |
8 | * Mimic system calls for: | |
9 | * - session creation, returns an object descriptor or failure. | |
10 | * - channel creation, returns an object descriptor or failure. | |
11 | * - Operates on a session object descriptor | |
12 | * - Takes all channel options as parameters. | |
13 | * - stream get, returns an object descriptor or failure. | |
14 | * - Operates on a channel object descriptor. | |
15 | * - stream notifier get, returns an object descriptor or failure. | |
16 | * - Operates on a channel object descriptor. | |
17 | * - event creation, returns an object descriptor or failure. | |
18 | * - Operates on a channel object descriptor | |
19 | * - Takes an event name as parameter | |
20 | * - Takes an instrumentation source as parameter | |
21 | * - e.g. tracepoints, dynamic_probes... | |
22 | * - Takes instrumentation source specific arguments. | |
23 | * | |
24 | * Dual LGPL v2.1/GPL v2 license. | |
25 | */ | |
26 | ||
27 | #include <ust/lttng-ust-abi.h> | |
28 | #include <urcu/compiler.h> | |
29 | #include <urcu/list.h> | |
30 | #include <ust/lttng-events.h> | |
1dbfff0c | 31 | #include <ust/usterr-signal-safe.h> |
f4681817 MD |
32 | #include "ust/core.h" |
33 | #include "ltt-tracer.h" | |
34 | ||
35 | /* | |
36 | * Object descriptor table. Should be protected from concurrent access | |
37 | * by the caller. | |
38 | */ | |
39 | ||
f4681817 MD |
40 | struct obj { |
41 | union { | |
42 | struct { | |
43 | void *private_data; | |
44 | const struct objd_ops *ops; | |
45 | int f_count; | |
46 | } s; | |
47 | int freelist_next; /* offset freelist. end is -1. */ | |
48 | } u; | |
49 | }; | |
50 | ||
51 | struct objd_table { | |
52 | struct obj *array; | |
53 | unsigned int len, allocated_len; | |
54 | int freelist_head; /* offset freelist head. end is -1 */ | |
55 | }; | |
56 | ||
57 | static struct objd_table objd_table = { | |
58 | .freelist_head = -1, | |
59 | }; | |
60 | ||
61 | static | |
62 | int objd_alloc(void *private_data, const struct objd_ops *ops) | |
63 | { | |
64 | struct obj *obj; | |
65 | ||
66 | if (objd_table.freelist_head != -1) { | |
67 | obj = &objd_table.array[objd_table.freelist_head]; | |
68 | objd_table.freelist_head = obj->u.freelist_next; | |
69 | goto end; | |
70 | } | |
71 | ||
72 | if (objd_table.len >= objd_table.allocated_len) { | |
73 | unsigned int new_allocated_len, old_allocated_len; | |
74 | struct obj *new_table, *old_table; | |
75 | ||
76 | old_allocated_len = objd_table.allocated_len; | |
77 | old_table = objd_table.array; | |
78 | if (!old_allocated_len) | |
79 | new_allocated_len = 1; | |
80 | else | |
81 | new_allocated_len = old_allocated_len << 1; | |
82 | new_table = zmalloc(sizeof(struct obj) * new_allocated_len); | |
83 | if (!new_table) | |
84 | return -ENOMEM; | |
85 | memcpy(new_table, old_table, | |
86 | sizeof(struct obj) * old_allocated_len); | |
87 | free(old_table); | |
88 | objd_table.array = new_table; | |
89 | objd_table.allocated_len = new_allocated_len; | |
90 | } | |
91 | obj = &objd_table.array[objd_table.len]; | |
92 | objd_table.len++; | |
93 | end: | |
94 | obj->u.s.private_data = private_data; | |
95 | obj->u.s.ops = ops; | |
a4be8962 MD |
96 | obj->u.s.f_count = 2; /* count == 1 : object is allocated */ |
97 | /* count == 2 : allocated + hold ref */ | |
f4681817 MD |
98 | return obj - objd_table.array; |
99 | } | |
100 | ||
101 | static | |
102 | struct obj *_objd_get(int id) | |
103 | { | |
104 | if (id >= objd_table.len) | |
105 | return NULL; | |
a4be8962 MD |
106 | if (!objd_table.array[id].u.s.f_count) |
107 | return NULL; | |
f4681817 MD |
108 | return &objd_table.array[id]; |
109 | } | |
110 | ||
111 | static | |
112 | void *objd_private(int id) | |
113 | { | |
114 | struct obj *obj = _objd_get(id); | |
115 | assert(obj); | |
116 | return obj->u.s.private_data; | |
117 | } | |
118 | ||
119 | static | |
120 | void objd_set_private(int id, void *private_data) | |
121 | { | |
122 | struct obj *obj = _objd_get(id); | |
123 | assert(obj); | |
124 | obj->u.s.private_data = private_data; | |
125 | } | |
126 | ||
f4681817 MD |
127 | const struct objd_ops *objd_ops(int id) |
128 | { | |
129 | struct obj *obj = _objd_get(id); | |
46050b1a | 130 | |
a4be8962 MD |
131 | if (!obj) |
132 | return NULL; | |
f4681817 MD |
133 | return obj->u.s.ops; |
134 | } | |
135 | ||
136 | static | |
137 | void objd_free(int id) | |
138 | { | |
139 | struct obj *obj = _objd_get(id); | |
140 | ||
141 | assert(obj); | |
142 | obj->u.freelist_next = objd_table.freelist_head; | |
143 | objd_table.freelist_head = obj - objd_table.array; | |
a4be8962 MD |
144 | assert(obj->u.s.f_count == 1); |
145 | obj->u.s.f_count = 0; /* deallocated */ | |
f4681817 MD |
146 | } |
147 | ||
148 | static | |
149 | void objd_ref(int id) | |
150 | { | |
151 | struct obj *obj = _objd_get(id); | |
152 | obj->u.s.f_count++; | |
153 | } | |
154 | ||
1ea11eab | 155 | int objd_unref(int id) |
f4681817 MD |
156 | { |
157 | struct obj *obj = _objd_get(id); | |
158 | ||
1ea11eab MD |
159 | if (!obj) |
160 | return -EINVAL; | |
a4be8962 MD |
161 | if (obj->u.s.f_count == 1) { |
162 | ERR("Reference counting error\n"); | |
163 | return -EINVAL; | |
164 | } | |
165 | if ((--obj->u.s.f_count) == 1) { | |
f4681817 | 166 | const struct objd_ops *ops = objd_ops(id); |
a4be8962 | 167 | |
f4681817 MD |
168 | if (ops->release) |
169 | ops->release(id); | |
170 | objd_free(id); | |
171 | } | |
1ea11eab | 172 | return 0; |
f4681817 MD |
173 | } |
174 | ||
175 | static | |
176 | void objd_table_destroy(void) | |
177 | { | |
a4be8962 MD |
178 | int i; |
179 | ||
180 | for (i = 0; i < objd_table.allocated_len; i++) { | |
181 | struct obj *obj = _objd_get(i); | |
182 | const struct objd_ops *ops; | |
183 | ||
184 | if (!obj) | |
185 | continue; | |
186 | ops = obj->u.s.ops; | |
187 | if (ops->release) | |
188 | ops->release(i); | |
189 | } | |
f4681817 | 190 | free(objd_table.array); |
17dfb34b | 191 | objd_table.freelist_head = -1; |
f4681817 MD |
192 | } |
193 | ||
194 | /* | |
195 | * This is LTTng's own personal way to create an ABI for sessiond. | |
196 | * We send commands over a socket. | |
197 | */ | |
198 | ||
199 | static const struct objd_ops lttng_ops; | |
200 | static const struct objd_ops lttng_session_ops; | |
201 | static const struct objd_ops lttng_channel_ops; | |
202 | static const struct objd_ops lttng_metadata_ops; | |
203 | static const struct objd_ops lttng_event_ops; | |
204 | ||
205 | enum channel_type { | |
206 | PER_CPU_CHANNEL, | |
207 | METADATA_CHANNEL, | |
208 | }; | |
209 | ||
46050b1a MD |
210 | int lttng_abi_create_root_handle(void) |
211 | { | |
212 | int root_handle; | |
213 | ||
214 | root_handle = objd_alloc(NULL, <tng_ops); | |
215 | assert(root_handle == 0); | |
216 | return root_handle; | |
217 | } | |
218 | ||
818173b9 | 219 | static |
f4681817 MD |
220 | int lttng_abi_create_session(void) |
221 | { | |
222 | struct ltt_session *session; | |
223 | int session_objd, ret; | |
224 | ||
225 | session = ltt_session_create(); | |
226 | if (!session) | |
227 | return -ENOMEM; | |
228 | session_objd = objd_alloc(session, <tng_session_ops); | |
229 | if (session_objd < 0) { | |
230 | ret = session_objd; | |
231 | goto objd_error; | |
232 | } | |
233 | session->objd = session_objd; | |
234 | return session_objd; | |
235 | ||
236 | objd_error: | |
237 | ltt_session_destroy(session); | |
238 | return ret; | |
239 | } | |
240 | ||
241 | #if 0 | |
242 | static | |
243 | int lttng_abi_tracepoint_list(void) | |
244 | { | |
245 | int list_objd, ret; | |
246 | ||
247 | /* TODO: Create list private data */ | |
248 | list_objd = objd_alloc(NULL, <tng_tracepoint_list_ops); | |
249 | if (list_objd < 0) { | |
250 | ret = list_objd; | |
251 | goto objd_error; | |
252 | } | |
253 | ||
254 | return list_objd; | |
255 | ||
256 | objd_error: | |
257 | return ret; | |
258 | } | |
259 | #endif //0 | |
260 | ||
261 | static | |
262 | long lttng_abi_tracer_version(int objd, | |
263 | struct lttng_ust_tracer_version *v) | |
264 | { | |
265 | v->version = LTTNG_UST_VERSION; | |
266 | v->patchlevel = LTTNG_UST_PATCHLEVEL; | |
267 | v->sublevel = LTTNG_UST_SUBLEVEL; | |
268 | return 0; | |
269 | } | |
270 | ||
271 | static | |
272 | long lttng_abi_add_context(int objd, | |
273 | struct lttng_ust_context *context_param, | |
274 | struct lttng_ctx **ctx, struct ltt_session *session) | |
275 | { | |
276 | if (session->been_active) | |
277 | return -EPERM; | |
278 | ||
279 | switch (context_param->ctx) { | |
280 | case LTTNG_UST_CONTEXT_VTID: | |
438bc215 | 281 | //TODO return lttng_add_vtid_to_ctx(ctx); |
f4681817 MD |
282 | default: |
283 | return -EINVAL; | |
284 | } | |
285 | } | |
286 | ||
287 | /** | |
288 | * lttng_cmd - lttng control through socket commands | |
289 | * | |
290 | * @objd: the object descriptor | |
291 | * @cmd: the command | |
292 | * @arg: command arg | |
293 | * | |
294 | * This descriptor implements lttng commands: | |
295 | * LTTNG_UST_SESSION | |
296 | * Returns a LTTng trace session object descriptor | |
297 | * LTTNG_UST_TRACER_VERSION | |
298 | * Returns the LTTng kernel tracer version | |
299 | * LTTNG_UST_TRACEPOINT_LIST | |
300 | * Returns a file descriptor listing available tracepoints | |
301 | * LTTNG_UST_WAIT_QUIESCENT | |
302 | * Returns after all previously running probes have completed | |
303 | * | |
304 | * The returned session will be deleted when its file descriptor is closed. | |
305 | */ | |
306 | static | |
307 | long lttng_cmd(int objd, unsigned int cmd, unsigned long arg) | |
308 | { | |
309 | switch (cmd) { | |
310 | case LTTNG_UST_SESSION: | |
311 | return lttng_abi_create_session(); | |
312 | case LTTNG_UST_TRACER_VERSION: | |
313 | return lttng_abi_tracer_version(objd, | |
314 | (struct lttng_ust_tracer_version *) arg); | |
315 | case LTTNG_UST_TRACEPOINT_LIST: | |
316 | return -ENOSYS; //TODO | |
317 | //return lttng_abi_tracepoint_list(); | |
318 | case LTTNG_UST_WAIT_QUIESCENT: | |
319 | synchronize_trace(); | |
320 | return 0; | |
321 | default: | |
322 | return -EINVAL; | |
323 | } | |
324 | } | |
325 | ||
326 | static const struct objd_ops lttng_ops = { | |
327 | .cmd = lttng_cmd, | |
328 | }; | |
329 | ||
330 | /* | |
331 | * We tolerate no failure in this function (if one happens, we print a dmesg | |
332 | * error, but cannot return any error, because the channel information is | |
333 | * invariant. | |
334 | */ | |
335 | static | |
336 | void lttng_metadata_create_events(int channel_objd) | |
337 | { | |
338 | struct ltt_channel *channel = objd_private(channel_objd); | |
339 | static struct lttng_ust_event metadata_params = { | |
340 | .instrumentation = LTTNG_UST_TRACEPOINT, | |
341 | .name = "lttng_metadata", | |
342 | }; | |
343 | struct ltt_event *event; | |
344 | int ret; | |
345 | ||
346 | /* | |
347 | * We tolerate no failure path after event creation. It will stay | |
348 | * invariant for the rest of the session. | |
349 | */ | |
350 | event = ltt_event_create(channel, &metadata_params, NULL); | |
351 | if (!event) { | |
352 | ret = -EINVAL; | |
353 | goto create_error; | |
354 | } | |
355 | return; | |
356 | ||
357 | create_error: | |
358 | WARN_ON(1); | |
359 | return; /* not allowed to return error */ | |
360 | } | |
361 | ||
f4681817 MD |
362 | int lttng_abi_create_channel(int session_objd, |
363 | struct lttng_ust_channel *chan_param, | |
364 | enum channel_type channel_type) | |
365 | { | |
366 | struct ltt_session *session = objd_private(session_objd); | |
367 | const struct objd_ops *ops; | |
368 | const char *transport_name; | |
369 | struct ltt_channel *chan; | |
370 | int chan_objd; | |
371 | int ret = 0; | |
372 | ||
373 | chan_objd = objd_alloc(NULL, <tng_channel_ops); | |
374 | if (chan_objd < 0) { | |
375 | ret = chan_objd; | |
376 | goto objd_error; | |
377 | } | |
378 | switch (channel_type) { | |
379 | case PER_CPU_CHANNEL: | |
380 | if (chan_param->output == LTTNG_UST_MMAP) { | |
381 | transport_name = chan_param->overwrite ? | |
382 | "relay-overwrite-mmap" : "relay-discard-mmap"; | |
383 | } else { | |
384 | return -EINVAL; | |
385 | } | |
386 | ops = <tng_channel_ops; | |
387 | break; | |
388 | case METADATA_CHANNEL: | |
389 | if (chan_param->output == LTTNG_UST_MMAP) | |
390 | transport_name = "relay-metadata-mmap"; | |
391 | else | |
392 | return -EINVAL; | |
393 | ops = <tng_metadata_ops; | |
394 | break; | |
395 | default: | |
396 | transport_name = "<unknown>"; | |
397 | break; | |
398 | } | |
399 | /* | |
400 | * We tolerate no failure path after channel creation. It will stay | |
401 | * invariant for the rest of the session. | |
402 | */ | |
403 | chan = ltt_channel_create(session, transport_name, NULL, | |
404 | chan_param->subbuf_size, | |
405 | chan_param->num_subbuf, | |
406 | chan_param->switch_timer_interval, | |
407 | chan_param->read_timer_interval); | |
408 | if (!chan) { | |
409 | ret = -EINVAL; | |
410 | goto chan_error; | |
411 | } | |
412 | objd_set_private(chan_objd, chan); | |
413 | chan->objd = chan_objd; | |
414 | if (channel_type == METADATA_CHANNEL) { | |
415 | session->metadata = chan; | |
416 | lttng_metadata_create_events(chan_objd); | |
417 | } | |
418 | ||
419 | /* The channel created holds a reference on the session */ | |
420 | objd_ref(session_objd); | |
421 | ||
422 | return chan_objd; | |
423 | ||
424 | chan_error: | |
1ea11eab MD |
425 | { |
426 | int err; | |
427 | ||
428 | err = objd_unref(chan_objd); | |
429 | assert(!err); | |
430 | } | |
f4681817 MD |
431 | objd_error: |
432 | return ret; | |
433 | } | |
434 | ||
435 | /** | |
436 | * lttng_session_cmd - lttng session object command | |
437 | * | |
438 | * @obj: the object | |
439 | * @cmd: the command | |
440 | * @arg: command arg | |
441 | * | |
442 | * This descriptor implements lttng commands: | |
443 | * LTTNG_UST_CHANNEL | |
444 | * Returns a LTTng channel object descriptor | |
445 | * LTTNG_UST_ENABLE | |
446 | * Enables tracing for a session (weak enable) | |
447 | * LTTNG_UST_DISABLE | |
448 | * Disables tracing for a session (strong disable) | |
449 | * LTTNG_UST_METADATA | |
450 | * Returns a LTTng metadata object descriptor | |
451 | * | |
452 | * The returned channel will be deleted when its file descriptor is closed. | |
453 | */ | |
454 | static | |
455 | long lttng_session_cmd(int objd, unsigned int cmd, unsigned long arg) | |
456 | { | |
457 | struct ltt_session *session = objd_private(objd); | |
458 | ||
459 | switch (cmd) { | |
460 | case LTTNG_UST_CHANNEL: | |
461 | return lttng_abi_create_channel(objd, | |
462 | (struct lttng_ust_channel *) arg, | |
463 | PER_CPU_CHANNEL); | |
464 | case LTTNG_UST_SESSION_START: | |
465 | case LTTNG_UST_ENABLE: | |
466 | return ltt_session_enable(session); | |
467 | case LTTNG_UST_SESSION_STOP: | |
468 | case LTTNG_UST_DISABLE: | |
469 | return ltt_session_disable(session); | |
470 | case LTTNG_UST_METADATA: | |
471 | return lttng_abi_create_channel(objd, | |
472 | (struct lttng_ust_channel *) arg, | |
473 | METADATA_CHANNEL); | |
474 | default: | |
475 | return -EINVAL; | |
476 | } | |
477 | } | |
478 | ||
479 | /* | |
480 | * Called when the last file reference is dropped. | |
481 | * | |
482 | * Big fat note: channels and events are invariant for the whole session after | |
483 | * their creation. So this session destruction also destroys all channel and | |
484 | * event structures specific to this session (they are not destroyed when their | |
485 | * individual file is released). | |
486 | */ | |
487 | static | |
1ea11eab | 488 | int lttng_release_session(int objd) |
f4681817 MD |
489 | { |
490 | struct ltt_session *session = objd_private(objd); | |
491 | ||
1ea11eab | 492 | if (session) { |
f4681817 | 493 | ltt_session_destroy(session); |
1ea11eab MD |
494 | return 0; |
495 | } else { | |
496 | return -EINVAL; | |
497 | } | |
f4681817 MD |
498 | } |
499 | ||
500 | static const struct objd_ops lttng_session_ops = { | |
1ea11eab | 501 | .release = lttng_release_session, |
f4681817 MD |
502 | .cmd = lttng_session_cmd, |
503 | }; | |
504 | ||
505 | #if 0 | |
506 | static | |
507 | int lttng_abi_open_stream(int channel_objd) | |
508 | { | |
509 | struct ltt_channel *channel = objd_private(channel_objd); | |
510 | struct lib_ring_buffer *buf; | |
511 | int stream_objd, ret; | |
512 | ||
513 | buf = channel->ops->buffer_read_open(channel->chan); | |
514 | if (!buf) | |
515 | return -ENOENT; | |
516 | ||
517 | stream_objd = objd_alloc(buf, &lib_ring_buffer_objd_ops); | |
518 | if (stream_objd < 0) { | |
519 | ret = stream_objd; | |
520 | goto objd_error; | |
521 | } | |
522 | /* | |
523 | * The stream holds a reference to the channel within the generic ring | |
524 | * buffer library, so no need to hold a refcount on the channel and | |
525 | * session files here. | |
526 | */ | |
527 | return stream_objd; | |
528 | ||
529 | objd_error: | |
530 | channel->ops->buffer_read_close(buf); | |
531 | return ret; | |
532 | } | |
533 | #endif //0 | |
534 | ||
535 | static | |
536 | int lttng_abi_create_event(int channel_objd, | |
537 | struct lttng_ust_event *event_param) | |
538 | { | |
539 | struct ltt_channel *channel = objd_private(channel_objd); | |
540 | struct ltt_event *event; | |
541 | int event_objd, ret; | |
542 | ||
543 | event_param->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0'; | |
544 | event_objd = objd_alloc(NULL, <tng_event_ops); | |
545 | if (event_objd < 0) { | |
546 | ret = event_objd; | |
547 | goto objd_error; | |
548 | } | |
549 | /* | |
550 | * We tolerate no failure path after event creation. It will stay | |
551 | * invariant for the rest of the session. | |
552 | */ | |
553 | event = ltt_event_create(channel, event_param, NULL); | |
554 | if (!event) { | |
555 | ret = -EINVAL; | |
556 | goto event_error; | |
557 | } | |
558 | objd_set_private(event_objd, event); | |
559 | /* The event holds a reference on the channel */ | |
560 | objd_ref(channel_objd); | |
561 | return event_objd; | |
562 | ||
563 | event_error: | |
1ea11eab MD |
564 | { |
565 | int err; | |
566 | ||
567 | err = objd_unref(event_objd); | |
568 | assert(!err); | |
569 | } | |
f4681817 MD |
570 | objd_error: |
571 | return ret; | |
572 | } | |
573 | ||
574 | /** | |
575 | * lttng_channel_cmd - lttng control through object descriptors | |
576 | * | |
577 | * @objd: the object descriptor | |
578 | * @cmd: the command | |
579 | * @arg: command arg | |
580 | * | |
581 | * This object descriptor implements lttng commands: | |
582 | * LTTNG_UST_STREAM | |
583 | * Returns an event stream object descriptor or failure. | |
584 | * (typically, one event stream records events from one CPU) | |
585 | * LTTNG_UST_EVENT | |
586 | * Returns an event object descriptor or failure. | |
587 | * LTTNG_UST_CONTEXT | |
588 | * Prepend a context field to each event in the channel | |
589 | * LTTNG_UST_ENABLE | |
590 | * Enable recording for events in this channel (weak enable) | |
591 | * LTTNG_UST_DISABLE | |
592 | * Disable recording for events in this channel (strong disable) | |
593 | * | |
594 | * Channel and event file descriptors also hold a reference on the session. | |
595 | */ | |
596 | static | |
597 | long lttng_channel_cmd(int objd, unsigned int cmd, unsigned long arg) | |
598 | { | |
599 | struct ltt_channel *channel = objd_private(objd); | |
600 | ||
601 | switch (cmd) { | |
602 | case LTTNG_UST_STREAM: | |
603 | return -ENOSYS; //TODO | |
604 | //return lttng_abi_open_stream(objd); | |
605 | case LTTNG_UST_EVENT: | |
606 | return lttng_abi_create_event(objd, (struct lttng_ust_event *) arg); | |
607 | case LTTNG_UST_CONTEXT: | |
608 | return lttng_abi_add_context(objd, | |
609 | (struct lttng_ust_context *) arg, | |
610 | &channel->ctx, channel->session); | |
611 | case LTTNG_UST_ENABLE: | |
612 | return ltt_channel_enable(channel); | |
613 | case LTTNG_UST_DISABLE: | |
614 | return ltt_channel_disable(channel); | |
615 | default: | |
616 | return -EINVAL; | |
617 | } | |
618 | } | |
619 | ||
620 | /** | |
621 | * lttng_metadata_cmd - lttng control through object descriptors | |
622 | * | |
623 | * @objd: the object descriptor | |
624 | * @cmd: the command | |
625 | * @arg: command arg | |
626 | * | |
627 | * This object descriptor implements lttng commands: | |
628 | * LTTNG_UST_STREAM | |
629 | * Returns an event stream file descriptor or failure. | |
630 | * | |
631 | * Channel and event file descriptors also hold a reference on the session. | |
632 | */ | |
633 | static | |
634 | long lttng_metadata_cmd(int objd, unsigned int cmd, unsigned long arg) | |
635 | { | |
636 | switch (cmd) { | |
637 | case LTTNG_UST_STREAM: | |
638 | return -ENOSYS; //TODO | |
639 | //return lttng_abi_open_stream(objd); | |
640 | default: | |
641 | return -EINVAL; | |
642 | } | |
643 | } | |
644 | ||
645 | #if 0 | |
646 | /** | |
647 | * lttng_channel_poll - lttng stream addition/removal monitoring | |
648 | * | |
649 | * @file: the file | |
650 | * @wait: poll table | |
651 | */ | |
652 | unsigned int lttng_channel_poll(struct file *file, poll_table *wait) | |
653 | { | |
654 | struct ltt_channel *channel = file->private_data; | |
655 | unsigned int mask = 0; | |
656 | ||
657 | if (file->f_mode & FMODE_READ) { | |
658 | poll_wait_set_exclusive(wait); | |
659 | poll_wait(file, channel->ops->get_hp_wait_queue(channel->chan), | |
660 | wait); | |
661 | ||
662 | if (channel->ops->is_disabled(channel->chan)) | |
663 | return POLLERR; | |
664 | if (channel->ops->is_finalized(channel->chan)) | |
665 | return POLLHUP; | |
666 | if (channel->ops->buffer_has_read_closed_stream(channel->chan)) | |
667 | return POLLIN | POLLRDNORM; | |
668 | return 0; | |
669 | } | |
670 | return mask; | |
671 | ||
672 | } | |
673 | #endif //0 | |
674 | ||
675 | static | |
676 | int lttng_channel_release(int objd) | |
677 | { | |
678 | struct ltt_channel *channel = objd_private(objd); | |
679 | ||
680 | if (channel) | |
1ea11eab | 681 | return objd_unref(channel->session->objd); |
f4681817 MD |
682 | return 0; |
683 | } | |
684 | ||
685 | static const struct objd_ops lttng_channel_ops = { | |
686 | .release = lttng_channel_release, | |
687 | //.poll = lttng_channel_poll, | |
688 | .cmd = lttng_channel_cmd, | |
689 | }; | |
690 | ||
691 | static const struct objd_ops lttng_metadata_ops = { | |
692 | .release = lttng_channel_release, | |
693 | .cmd = lttng_metadata_cmd, | |
694 | }; | |
695 | ||
696 | /** | |
697 | * lttng_event_cmd - lttng control through object descriptors | |
698 | * | |
699 | * @objd: the object descriptor | |
700 | * @cmd: the command | |
701 | * @arg: command arg | |
702 | * | |
703 | * This object descriptor implements lttng commands: | |
704 | * LTTNG_UST_CONTEXT | |
705 | * Prepend a context field to each record of this event | |
706 | * LTTNG_UST_ENABLE | |
707 | * Enable recording for this event (weak enable) | |
708 | * LTTNG_UST_DISABLE | |
709 | * Disable recording for this event (strong disable) | |
710 | */ | |
711 | static | |
712 | long lttng_event_cmd(int objd, unsigned int cmd, unsigned long arg) | |
713 | { | |
714 | struct ltt_event *event = objd_private(objd); | |
715 | ||
716 | switch (cmd) { | |
717 | case LTTNG_UST_CONTEXT: | |
718 | return lttng_abi_add_context(objd, | |
719 | (struct lttng_ust_context *) arg, | |
720 | &event->ctx, event->chan->session); | |
721 | case LTTNG_UST_ENABLE: | |
722 | return ltt_event_enable(event); | |
723 | case LTTNG_UST_DISABLE: | |
724 | return ltt_event_disable(event); | |
725 | default: | |
726 | return -EINVAL; | |
727 | } | |
728 | } | |
729 | ||
730 | static | |
731 | int lttng_event_release(int objd) | |
732 | { | |
733 | struct ltt_event *event = objd_private(objd); | |
734 | ||
735 | if (event) | |
1ea11eab | 736 | return objd_unref(event->chan->objd); |
f4681817 MD |
737 | return 0; |
738 | } | |
739 | ||
740 | /* TODO: filter control ioctl */ | |
741 | static const struct objd_ops lttng_event_ops = { | |
742 | .release = lttng_event_release, | |
743 | .cmd = lttng_event_cmd, | |
744 | }; | |
745 | ||
b35d179d | 746 | void lttng_ust_abi_exit(void) |
f4681817 | 747 | { |
f4681817 MD |
748 | objd_table_destroy(); |
749 | } |